Cryptozoology is not the science
of giant unknown animals, as misinformed people (including some
cryptozoologists) believe. The wrongness of this received idea has
been demonstrated, with figures in support, by Bernard
Heuvelmans (1986, 1987) and by Raynal (1987). Of course, living
brontosaurs strike our imagination, but the size of the unknown
animals we are dealing with, cannot be a criterium, and little
unknown animals should not be neglected (and in fact their existence
is often much more likely than these "monsters").
It is true that a minimum size is generally required. As
cryptozoology is mainly based on sightings by laymen, an unknown
animal should be of a sufficient size to be observed, and recognized
as such (i.e. unknown). Of course, if a layman observes an animal
unknown to science, only the size of a sparrow, it is likely that he
will not realize that he is observing an unknown animal, unless he is
a specialist of the zoological group in question. On the other hand,
if he observes a very large animal, he will have some reason to
suppose that it is an unknown creature : this is a simple matter of
fact, but not a strict rule : special colours, a strange behaviour,
an anatomical detail, etc., are also likely to catch the
laymans attention.
As the size is not a criterium to state what is cryptozoological and
what is not, Bauer and Russell (1988) have thus suggested an
intensive research in what they call "microcryptozoology", that is to
say the search for little unidentified animals, but Dethier and
Dethier-Sakamoto (1988) noticed :

"We entirely agree with Bauer
and Russell when they point out the importance of searching for
small and discrete unknown animals. If they are not ethnoknown,
however, they are, of course, outside the scope of
cryptozoology."

This statement, though often true, is not an absolute rule. The
definition of cryptozoology by Heuvelmans
(1988) is much less restrictive :

"The scientific study of
hidden animals, i.e. of still unknown animal forms about which
only testimonial and circumstancial evidence is available, or
material evidence considered insufficient by some."

As a consequence, a cryptozoological research is still possible
when no observation or native tradition is available : any
information based on circumstancial evidence, allowing to forsee the
existence of an unknown animal form, is relevant to
cryptozoology.
It is the case for a very little animal -- a moth ! -- the story of
which is one of the most remarkable victories of a true
cryptozoological mind, though it is, curiously enough, unknown to
most cryptozoologists...
For its opponents, cryptozoology is nothing else than a hunt for wild
geese, as it has never obtained any positive result. This statement,
often repeated, shows either a great ignorance of the history of
zoology, or a deliberate dishonesty : the giant squid
(Architeuthis), the okapi
(Okapia johnstoni) and the Congo
peacock (Afropavo congensis) -- to mention these three
animals only -- had been "cryptozoologically" predicted. And the
author has published an impressive list of the recent victories of
cryptozoology for the years 1986-1996 (Raynal 1989, 1996).

The predicted moth

In 1862, the famous naturalist Charles Darwin (figure 1) published
a book on the evolutionary biology of orchids, On the Various
Contrivances by which British and Foreign Orchids are Fertilised by
Insects. Studying the angraecoids, he remarked that they were
pollinisated by specific insects. One of these orchids from
Madagascar, Angraecum sesquipedale, had nectaries eleven and a half
inches (28.6 cm) long, with only the lower inch and a half (3.8 cm)
filled with nectar. From the structure of this orchid, Darwin
"predicted" the existence of an unknown moth :

"It is, however, surprising
that any insect should be able to reach the nectar : our
English sphinxes have probosces as long as their bodies ; but
in Madagascar there must be moths with probosces capable of
extension to a length of between ten and eleven inches !"
(Darwin 1862).

Figure 1 : Charles Darwin (1809-1882)

Darwin then made an experiment. He took a cylinder, one-tenth of
an inch (2.5 mm) in diameter, and pushed it down through the cleft of
the rostrellum :

"By this means alone I
succeeded in each case in withdrawing the pollinia ; and it
cannot, I think, be doubted that a large moth must thus act ;
namely, by driving its proboscis up to the very base, through
the cleft of the rostrellum, so as to reach the extremity of
the nectary ; and then withdrawing its proboscis with the
pollinia attached to it."

This insect would affect of course the fertilization of the
orchid, and Darwin concluded to the survival of this moth from
ecological evidence :

"The pollinia would not be
withdrawn until some huge moth, with a wonderfully long
proboscis, tried to drain the last drop. If such great moths
were to become extinct in Madagascar, assuredly the
Angraecum would become extinct."

In a letter published in the June 12, 1873, issue of
Nature, W.A. Forbes asked if readers were aware of such moths
in Madagascar, and he proposed an identification :

"They would probably be
Sphingidae of some kind, as no other moths would combine
sufficient size and length of proboscis." (Forbes 1873).

Herman Müller, in the July 17 issue of the same year,
mentioned that his brother had caught in Brazil a sphinx "the
proboscis of which has a length of about 0.25 metres", demonstrating
that Darwin's moth was not at all impossible (Müller 1873). In
the second edition of his book (1877), the father of natural
selection remarked :

"This belief of mine has been
ridiculed by some entomologists, but we now know from Fritz
Müller that there is a sphinx-moth in South Brazil which
has a proboscis of nearly sufficient length, for when dried it
was between ten and eleven inches long. When not protruded it
is coiled up into a spiral of at least twenty windings."
(Darwin 1877).

Meanwhile, Alfred Russel Wallace (figure 2), the father of
biogeography, commented at greater length on this orchid, firstly in
an article for the Quarterly Journal of Science (1867), then
in his book Contributions to the Theory of Natural Selection
(1871), and he came to the same conclusion :

"I may here mention that some
of the large sphinx moths of the tropics have probosces as long
as the nectary of Angraecum sesquipedale. I have
carefully measured the proboscis of a specimen of Macrosilia
cluentius [=Cocytius cluentius] from South
America, in the collections of the British Museum, and find it
to be nine inches and a quarter long ! One from tropical Africa
(Macrosilia morgani) [=Xanthopan morgani]
is seven inches and a half. [...]. That such a moth
exists in Madagascar may be safely predicted ; and naturalists
who visit that island should search for it with as much
confidance as astronomers searched for the planet Neptune, and
I venture to predict they will be equally successful !"
(Wallace 1867, 1871).

Figure 2 : Alfred Russel Wallace (1823-1913)

This last remark alluded to German astronomer Galle, who had
searched for, and found, the planet Neptune, after French
mathematician Le Verrier predicted its existence and position, from
calculations on the orbite of Uranus, the then last known planet of
the solar system -- a well-known case in the history of sciences,
often mentioned for its significance in epistemology.
And the idea of a close relation with the large sphingid of tropical
Africa, Xanthopan morgani, which has a proboscis about 20 cm,
was quite judicious and prophetic. This "cryptolepidoptere" was
actually found and described 41 years after Darwin's prediction : it
belonged to that very species, but it was a new sub-species, which
Rothschild and Jordan named Xanthopan morgani praedicta in
1903, i.e. "predicted",which is fully justified (Rothschild and
Jordan 1903). This insect has a wing span of 13 to 15 cm, of the
color of a dead leaf and its proboscis is actually 25 cm (ten inches)
long (figure 3).

This contribution to cryptozoology is remarkable, as it concerns
the prediction, from phytobiology and ecology (i.e. from
circumstancial evidence only), of an unknown moth (at the level of
the subspecies), the existence and the identification of which have
been experimentally confirmed a posteriori. This should be
considered an important victory of a true cryptozoological mind,
shared at least by two of the greatest naturalists of the nineteenth
century, to wit Darwin and Wallace.

A second unknown moth ?

History now seems to be repeating itself : American entomologist
Gene Kritsky, of the Mount Saint Joseph on the Ohio College in
Cincinnati, recently made an hypothesis similar to Darwin's
prediction. Another Madagascar orchid, Angraecum longicalcar,
has a rostrellum still deeper than that of A. sesquipedale :
about 16 inches (40 cm). Consequently, Gene Kritsky predicted in the
American Entomologist of Winter 1991 the existence of another
unknown large moth in Madagascar, with a proboscis 15 inches (38 cm)
long ! (Kritsky 1991, Angier 1992).

Let us hope that we will not have to wait 41 years before this new
predicted moth will be found...

Acknowledgements

Many thanks for their kind help to Marcel Lecoufle
(orchidophilist, Boissy Saint-Léger, France), Gene Kritsky
(Mount Saint Joseph on the Ohio College, Cincinnati), and
Joël Minet and Jean Orousset (both from the laboratory of
Entomology, Muséum National d'Histoire Naturelle,
Paris).